Originally Posted by
aroa
I would like the 'oxy bottle theorist' to tell where/ what part of the flight regime that the bottle failed in??
I'm not 'the 'oxy bottle theorist'' but if you look at the where the two crew oxygen system bottles on the B777 are located the theory is not without some merit. The hypothesised failure of an oxy bottle on MH370 would have been just after TOC about 40 minutes into the flight (on QF30 it was 55 minutes into the flight).
Originally Posted by
aroa
And with that failure what would be the initial result that would lead to bringing the a/c down.?
Unlike the B747 the oxygen bottles on the B777 aren't arrayed vertically in a cargo compartment, they are stacked horizontally in the main equipment centre. Directly ahead of the bottles in the MEC is the E3 rack on which you will find, inter alia, the left AIMS cabinet and the ADIRU. Directly behind the bottles is the E1 rack on which you will find, inter alia, the left VHF XCVR, the left transponder, the left Generator Control Unit, the left Primary Flight Computer and the Audio Management Unit.
If a bottle fails in a B777 it won't simply punch a hole in the aircraft, it will almost certainly take out a stack of fairly important systems that includes items like comms and transponder.
The other big difference is that those bottles are connected to the flight crew, not the passenger, emergency oxygen system. If one fails you would expect to loose the whole system. We know that it took QF30 38 seconds to start their emergency descent after their bottle failed (35 seconds after the cabin pressure warning commenced). If there was a bottle failure on MH370 and the damage punctured the hull, when the crew donned their masks they would not have been getting oxygen. Under those circumstances a hypoxic crew would not inconceivable.
I'm not going to play hypotheticals on every aspect of the flight but suffice to say that the oxygen bottle theory is, as I've noted, not without some merit.